1. Field of the Invention
The present invention relates to a portable terminal.
2. Description of the Related Art
A portable terminal is known as for example a mobile phone, a portable information terminal which can be held and operated by both hands of a user, or the like.
The portable terminals are classified into mono-form type ones, foldable type ones, and stretchable type ones.
The foldable type and stretchable type portable terminals are known from, for example, Japanese Patent Application (KOKAI) Publication No. 2007-6146. The stretchable type portable terminal is provided with a first casing and a second casing. The first casing has an approximately rectangular shape and includes a first wiring board and a first operation portion. The second casing also has an approximately rectangular shape, a size of which is approximately equal to that of the first casing, and includes a second wiring board electrically connected to the first wiring board and a second operation portion. The second casing is supported to the first casing by a casing linear movement guiding mechanism interposed between the first casing and the second casing, so that the second casing can be movable linearly along a longitudinal direction of the first casing between a stacking position where the second casing is stacked under the first casing and an extended position where the second casing is extended from one end which is a part of a peripheral surface of the first casing.
The conventional casing linear movement guiding mechanism is interposed between the first casing and the second casing, so that the guiding mechanism is passed through flat surfaces of the first and second casings facing each other. Further, the guiding mechanism is positioned at an approximately center position of each of the first and second casings in their lateral directions. Accordingly, the conventional guiding mechanism requires relatively large volumes in respective internal spaces of the first and second casings, and makes arrangements of the first and second wiring boards in the respective internal spaces of the first and second casings being difficult. As a result of this, it is difficult to further thin respective sizes (“thicknesses”) of the first and second casings in a direction (“thickness direction”) where the first casing and the second casing are stacked on one another.